The Boeing C-17 Globemaster III strategic airlifter is by far one of the biggest fuel consuming aircraft in U.S. Air Force fleet due to its...
The Boeing C-17 Globemaster III strategic airlifter is by far one of the biggest fuel consuming aircraft in U.S. Air Force fleet due to its high utilization rate to deliver troops and cargoes to U.S. bases around the world.
Since the type's first flight in 1991, worldwide fleet of 279 C-17 ever produced had crossed 3 million flight hours.
A small reduction in fuel consumption on each aircraft can save millions of dollars as USAF currently operates 222 of the type.
Hence USAF is trialing structural modifications to reduce fuel consumption, through the Air Force Research Laboratory’s C-17 Drag Reduction Program.
The 418th Flight Test Squadron based at Edwards air force base, California is currently wrapping up testing with the final three phases – out of five total – using 3-D printed parts by Lockheed Martin.
The squadron is testing parts in various configurations to see if the external structure modifications can improve airflow around the airplane.
During computational fluid dynamics simulations and wind tunnel tests, areas on the C-17 were identified that showed excessive drag and were targeted for optimization.
In the spring, the first two phases of testing were completed. Those tests were conducted with two different configurations of parts made by Vortex Control Technologies.
“A 1 percent improvement in drag reduction will result in 7.1 million gallons of fuel reduction per year,” said Bogdan Wozniak, the 418th FLTS, project engineer. “One to 2 percent drag reduction could translate to $24-48 million dollars in fuel savings per year.”
Currently, the team is preparing to test the fifth and final configuration using the Lockheed Martin parts.
They have recently tested the third and fourth phases, which consisted of placing 12 microvanes toward the aft of the C-17 for phase three and then adding three fairings to each wing for phase four.
The fifth phase will keep the 12 microvanes and six total fairings with the addition of two fairings on each winglet.
At least three flight tests are conducted with each phase – a flying qualities regression flight and cruise performance flights at .74 and .77 Mach.
The team will also conduct airdrop tests in December to ensure the microvanes do not interfere with the C-17’s airdrop mission.
The data collected will be sent to AFRL at Wright-Patterson Air Force Base, Ohio, to see if any of the modifications increase streamlining and reduce drag. Then, Air Force leaders will ultimately decide whether or not any of the modifications should be implemented throughout the C-17 fleet.
The test team at Edwards AFB consists of 412th Test Wing personnel, Lockheed Martin and Boeing contractors along with representatives from Canada, the U.K. and Australia, who have a stake in the program.
The final flight for the C-17 Drag Reduction Program is expected to happen in December.
Since the type's first flight in 1991, worldwide fleet of 279 C-17 ever produced had crossed 3 million flight hours.
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| (U.S. Air Force photo/Kenji Thuloweit) |
A small reduction in fuel consumption on each aircraft can save millions of dollars as USAF currently operates 222 of the type.
Hence USAF is trialing structural modifications to reduce fuel consumption, through the Air Force Research Laboratory’s C-17 Drag Reduction Program.
The 418th Flight Test Squadron based at Edwards air force base, California is currently wrapping up testing with the final three phases – out of five total – using 3-D printed parts by Lockheed Martin.
The squadron is testing parts in various configurations to see if the external structure modifications can improve airflow around the airplane.
During computational fluid dynamics simulations and wind tunnel tests, areas on the C-17 were identified that showed excessive drag and were targeted for optimization.
In the spring, the first two phases of testing were completed. Those tests were conducted with two different configurations of parts made by Vortex Control Technologies.
“A 1 percent improvement in drag reduction will result in 7.1 million gallons of fuel reduction per year,” said Bogdan Wozniak, the 418th FLTS, project engineer. “One to 2 percent drag reduction could translate to $24-48 million dollars in fuel savings per year.”
Currently, the team is preparing to test the fifth and final configuration using the Lockheed Martin parts.
They have recently tested the third and fourth phases, which consisted of placing 12 microvanes toward the aft of the C-17 for phase three and then adding three fairings to each wing for phase four.
The fifth phase will keep the 12 microvanes and six total fairings with the addition of two fairings on each winglet.
At least three flight tests are conducted with each phase – a flying qualities regression flight and cruise performance flights at .74 and .77 Mach.
The team will also conduct airdrop tests in December to ensure the microvanes do not interfere with the C-17’s airdrop mission.
The data collected will be sent to AFRL at Wright-Patterson Air Force Base, Ohio, to see if any of the modifications increase streamlining and reduce drag. Then, Air Force leaders will ultimately decide whether or not any of the modifications should be implemented throughout the C-17 fleet.
The test team at Edwards AFB consists of 412th Test Wing personnel, Lockheed Martin and Boeing contractors along with representatives from Canada, the U.K. and Australia, who have a stake in the program.
The final flight for the C-17 Drag Reduction Program is expected to happen in December.
